And here is another bug report for the latest Alpha...
This latest Alpha breaks BatchMux completely (at least for me). Took me a while to find it because the change log did not mention any changes to BatchMux.
The BatchMux log file says that there is no reference to the first video file. The relevant log files are here:
http://www30.zippyshare.com/v/6nkm21Zp/file.html
I then went back to the previous Alpha from 170921, and this version worked using identical settings. Something with the script creation for BatchMux must be broken.
Cheers
manolito